Autophosphorylation of the DNA-dependent protein kinase catalytic subunit is required for rejoining of DNA double-strand breaks
Autophosphorylation of the DNA-dependent protein kinase catalytic subunit is required for rejoining of DNA double-strand breaks
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DOI：
10.1101/gad.1015202
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发表时间：
2002-09-15
影响因子：
10.5
通讯作者：
Chen, DJ
中科院分区：
文献类型：
--
作者：
Chan, DW;Chen, BPC;Chen, DJ
非同源末端连接（NHEJ）是哺乳动物细胞中修复DNA双链断裂（DSB）的主要途径。DNA依赖性蛋白激酶（DNA-PK）由Ku和DNA-PK催化亚基（DNA-PKcs）组成，在体外被DNA激活，是NHEJ所必需的。我们报告说，DNA-PKcs是自动磷酸化的Thr 2609在体内的Ku依赖性的方式在电离辐射的反应。DNA损伤后磷酸化DNA-PKcs与γ-H2 AX和53 BP 1共定位。Thr 2609突变为Ala导致辐射敏感性和受损的DSB再连接。这些发现证实了NHEJ修复DSB需要在Thr 2609处的DNA-PKcs的Ku依赖性磷酸化。
Nonhomologous end-joining (NHEJ) is the predominant pathway that repairs DNA double-strand breaks (DSBs) in mammalian cells. The DNA-dependent protein kinase (DNA-PK), consisting of Ku and DNA-PK catalytic subunit (DNA-PKcs), is activated by DNA in vitro and is required for NHEJ. We report that DNA-PKcs is auto-phosphorylated at Thr2609 in vivo in a Ku-dependent manner in response to ionizing radiation. Phosphorylated DNA-PKcs colocalizes with both gamma-H2AX and 53BP1 after DNA damage. Mutation of Thr2609 to Ala leads to radiation sensitivity and impaired DSB rejoining. These findings establish that Ku-dependent phosphorylation of DNA-PKcs at Thr2609 is required for the repair of DSBs by NHEJ.